Automatic iris control by camera film magazine



July 13, 1965 AUTOMATIC IRIS co B. S. BENSON NTROL BY CAMERA FILM MAGAZINE Filed June 27, 1962 FIG. 5. fao@ FIG. 9.

INVENTOR W fm,

ATTORN EYS.

means;

United States Patent D This invention relates to cameras and more particularly to cameras having removeable magazines or cascttes for holding film and each of which can be removed and replaced with another holding a film of different speed, and the invention provides improved means on the casette for regulating light responsive means or the camera in accordance with the speedof the lilm in each casette.

t it is an object ot the invention to provide an improved camera construction in which there are light responsive means for determining the proper exposure of a iilm in the camera, and there are a group or film casettes that fit into the housing of the camera and that have means thereon, at different positions corresponding to the speed ot the film in the casette, for iniluencing the operati n of the light responsive means.

ln the prete-tred construction, the light responsive means includes electric circuitry with a plurality of switches, and the different casettes have abutments at different locations, corresponding to the speed ot the lm in the casette, for closing diiicrent parts of the electric circuitry. The circuitry preferably includes impedance units and diiterent impedance is inserted into the active part of the circuitry depending uponwhich switch or switches are closed.

lt is .an object ot the invention to provide an improved camera having an iris diaphragm and automatic light responsive means for controlling the iris diaphragm, and to change the position of the iris diaphragm foryany condition of light in accordance with different film casettes that are inserted selectively into the camera and that have films of different speeds in the dilerent casettes.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

In the drawing, forming a part hereof7 in which like reference characters indicate corresponding parts in all the views;

-iFlGURE l isk a diagrammatic top plan view, partly broken away and in section, showing a camera equipped with a iilm casette and with the control means of this invention for reguiating the operation of light responsive FGURE 2 is a front View oi the casette shown in FiGURE l;

`FltURES 36 are views, similar to FIGURE 2 but on a reduced scale, showing other casettes oi a group which are intended for holding lilms of dilierent speeds;

FGURE 7 is .a diagrammatic View of an iris control mechanism which may be used in the camera shown in FIGURE l;

Fl-G RE 8 is a rear View of the camera shown in FIG- URE l, with the casette removed in order to show the switches that are operated by the insertion of diierent casettes into the camera; and

FGURE 9 is a wiringdiagram for the camera shown in FEGURES 1 and 8.

rthe invention includes a camera il having a housing 'll in which there is a lens housing lll. Light enters the camera housing llthr-ough an opening ld in a front wall or" the housing and the light passes through the lens, which may be made up of a number of components in accordance with conventional practice. f

At an intermediate location along the length o the lens housing there is an iris control device le. At the khaelt of the lens housing le there is a iilm casette 2li which ats/idas ICC fits yinto the back of the camera housing ll. yIn FIGURE l the r'ilrn casette is shown in full lines inserted only part way into the camera housing ll and the position of the casette 2d, when fully inserted into ther housing ll, iS indicated by dotted lines.

The detailed construction of the film casette 2e need not be explained for a full understanding of this invention. lt is suilicient to understand that the iilm casette Ztl includes a supply spool 22 and a take-up spool 24. Film passes from the supply spool 21d across the inside surface of a front wall of the casette, this front wall being desighated by thek reference character 2d in FIGURE 2 where the outside ot the wall is shown. There is a sloty ZS in the wall Zd, and the nlm is exposed as it passes across the slot 28 on its way to the ta e-up spool 24. rlhe camera is intended for use with lihn having sprocket openings on both sides and there are slots 3d and 32 extending lengthwise ot the film at opposite ends ot the exposure slot ZS. These slots 3l? and 32 provide clearance for a driving sprocket which advances the film past the slot Z3 and for another sprocket which measures the amount of film used.

Considering the invention in its broader aspects, the tilm casette Ztl Iis merely representative of removeable lm magazines which can be inserted into a camera and removed from the camera to make way for a different magazine which is loaded with different kind of iihn. For example, one magazine may contain black and White film and another may contain color hlm. Also different magazines may be loaded with films of different speeds for use with different kinds of work. y

rthey iris control device i8 is connected with light responsive means 3d. ln the preferred embodiment of the invention this light responsive means 34 is a solar cell which supplies power to operate the iris control device, the amount of power suppl-fied being proportional to the intensity of the light which strikes the light responsive' device 3ft.

`For any given intensity ot light it is desirable that the light responsive device 3d produce different eiifects on the iris control device l@ depending upon the speed of the nlm which is in the camera. Even though the light intensity is exactly the same at two different times, it iS desireabl-e to have the iris control device admit less light to the ilrn it a faster hn is in the camera. ln order to obtain this control and have it dependent upon the speed of the ill-m, means are provided by which the casette 29 controls the etect oi the light responsive device 3d on the iris control device 1S. t

ln the construction illustrated, there is a switch d@ in the circuit of the iight responsive device 3d. This switch inclu 1es a tlrred electric contact and a movable electric contact dit carried by a spring dd which has a bias holding the Contact spaced from the xed coritact There is an abutment itl on the front of the casette 2d in position to touch the switch contact 4d and to push it into contactwith the other switch contact d2, thus closing ythe circuit through the switch d0. In FGURE l, the casette lil is shown in full lines in a position not fully inserted into the camera housing ll. so as to illustrate the abutment t3 spaced from the electric contact ed, and so as to show the contacts 44 and i2 in their normal spaced relation. As the film casette 2@ moves from the full line position to the dotted line position, shown in liGURE l, the contact td ahuts against the movableswitch contact ff-fl and this displaces this contact ld until it touches the Contact 42, as previously explained. v t

FEGURE 9 is a wiring diagram showing the location of the switch -ttl in the circuitry which connects the light responsive device 2id with the iris control device The electric circuitry includes a conductor 5'@ which snoeien connects the solar cell of the light responsive device 3d.- directly with a coil 52 of the iris control device i8. On the other side of the coil 52 there is another conductor 54 connecting the coil directly with the solar cell. rihe switch is connected in parallel with the coil 52 and is connected in series with an impedence unit do, preterably a resistor.

rthere are other iinpedence units ol, 62, 63 and de connected in series with the impedence unit 5d. Beyond the impedence unit di, there is a switch 65 which connects the impedence unit oil with the conductor Beyond the impedance unit 62 there is another switch o8 which connects the impedence unit 62 with the conductor 54. Beyond the impedence units d3 and 64 there are other switches 7) and '72 respeciveiy which connect these impedence units and ed with the conductor The switches ed, d3, t and 72 are preferably of the same construction as the switch With all of the switches i1-G, do, 6d, iti and 72 in their normal open position, the full voltage of the solar cell is impressed upon the coil 52 of the iris control device i3. When a casette is inserted into the camera and there is no switch operating abutment on the casette, then the iris diaphragm will be in its widest open position for any given intensity of light striking the solar cell. Thus a film casette, whch is loaded with the slowest film for which the camera is intended, will have no abutment tor operating any ot the switches dit, 66, 68, 7d or '72.

When the film casette 2Q is inserted into the camera, `and the switch d@ is closed, there is a circuit from the conductor 5t? through the iinpedence unit and through the switch it? to the conductor 5d. Since this circuit is in parallel with the coi m some of the current which `would otherwise iiow through the coil 52 is shunted through the impedence unit S6 and switch and this reduces the voltage and current supplied to the iris control device l with the result that the iris control device requires a stronger intensity of light on the solar cell to produce the same results that were produced when the switch iti was open.

Since the circuit through the switch i6 contains less impedence than any of the other circuits in parallel with the iris control coil 52, the casette 2@ which closes the switch 4) is use-d for holding the fastest hlm for which the camera is used.

When the switch 66 is closed and all of the other switches are open, then there are two impedence units 56 and Si in series with the switch tid in the shunt ciruit across the iris control coil SZ. Similarly, when the switch 5S is closed and the other switches are open, there are three impedence units 5d, dit and 62 in series in the shunt circuit across the coil 52. When the switch 72 is closed, and all the other switches are open, then all of the impedance units do, 6l, d2, d3 and ed are in series in the shunt circuit across the coil 52. Thus the closing of the switch 72 reduces the voltage on the coil 52 less than the closing of any of the other switches.

FEGURE 3 shows a casette 2da with an abutment in position to close the switch no (EEG-URE 9). HG- URE 4 shows a casette Zub with an abutment 48h in position to close the switch ed (FIGURE 9). FGURE 5 shows a casette 29C with an abuti ent 48C in position to close the switch 70 (FIGURE 9); and FGURE 6 shows a casette 29d with an abutment 43d in position to close the switch 72 (FGURE 9).

FIGURE 8 is a rear view of the camera shown in FIG- URE l and illustrates an opening K into which the casette Ztl or the other casettes 26a-d are inserted. This view also shows the locations of the switches dit, do, 63, '79 and 72 in a vertical line near one side of the opening 76 and in the path of the various abutments 48, etc., ot the various casettes.

FIGURE 8 also shows sockets '73 and '79 at the lower part of the opening and in position to receive rounded lower ends di and 82 at the lower end ot the spools 22 and Zd. These spools 2?. and 2d are yieldable in a vertical direction so that the rounded ends 8l and 32 can be displaced upwardly far enough to slide into the rounded depressions 73 and 79 (FIGURJJ 8 and to engage these depressions in the manner of ball detents. This detent action causes the spool ends Si and 82 to act as retaining means for holding the casette in the camera. But the casette can be withdrawn any time by merely exerting sufficient pull on it to displace the rounded ends Si and 82 from the depressions 7S and 79. These depressio s 7S and "i9 are in portions of thc camera which can be used for rotating the spool and in the preferred construction the recess or depression which is engaged by the takeup spool is constructed to provide a jaw clutch for driving the take-up spool but this forms no part of the present invention.

Again considering the invention in its broadest aspects, the light responsive device 34 and the iris control device may be considered as representative of means for determining the correct exposure forfilm in the camera, and instead of controlling the iris diaphragm, such means may control a shutter speed or may merely indicate to the user of the camera the exposure condi-tions that should be followed in operating the camera under any condition oi light intensity.

Tie camera illustrated in FIGURES l and 8 is a panoramic camera and is constructed so as to rotate about a vertical axis through a principal point of the lens. This means that the image at the focal plane of the camera remains stationary in space as the camera moves angularly about its axis of rotation. The hlm, which is also at the focal plane, can remain stationary in space as the casette 2d moves as a unit with the camera housing il and causes the exposure slot 2S (FIF- URE 2) to travel across the iilm. Such a camera does not require a shutter and the space between successive pictures will be an exposed area of film having the width of the slot 25a. The exposure time when the camera is taking a picture depends upon the rate of angular movement of the camera and upon the width ot' the slot 2S.

This invention is not limited to panoramic cameras, however, and it can be used with other cameras which have magazines or casettes and which have shutters for controlling the exposure of the film.

The preferred embodiment of the invention has been illustrated and described, but changes and modiiications can he made, and some features can be used in dierent combinations without departing from the invention as defined in the claims.

What is claimed is:

i. A camera including a housing having' a space therein, light-responsive means in the housing for determining proper exposure of a lm in the camera, the lightresponsive means including different electric circuits for changing the operation of said light-responsive means and including also a plurality or Switches in the circuits and at spaced locations at one side of said space in the housing, a gr u of film magazines that fit into the housing and into the back of said space within the housing and that are selectively inserted in the housing to change the lm in the camera, each ilm magazine having film spool housings at opposite sides thereof and a rearwardly recessed front wali between the housings and with an exposure slot therein for exposing a i'ilm that is drawn across the back of said recessed front wall, and an abutment surface on the film spool housing on one side of each of the magazines, location of the abutment surfaces of the different magazines corresponding with the location of different ones of the spaced switches, which switches close the circuits that adjust the camera for the particular film speeds of the films in the different magazines.

2. The camera described in claim l characterized by impedances in the dii'lerent electric circuits, the switch means being correlated with the dilerent electric circuits -to introduce dilerent impedance into the circuit of the light-responsive means upon selective operation of the diterent switches.

3, The camera described in claim 1 characterized by light-responsive means including an energy-generating element exposed to the light to be evalua-ted and an irisoperating device connected t0 the energy-generating element, dierent impedances in the different electric circuits, the different switches being in position to cut the impedences out of the circuit of the magg/generating device when there is no magazine in the camera and to introduce the different impedances into the circuit of the energy-generating element to vary the voltage .available to the iris-operating device in accordance with the position of the abutment on the particular magazine that is inserted into the camera.

References Cited bythe Examiner UNITED STATES PATENTS 2,080,055 5/37 Martin 95-10 X 2,493,928 1/50 Rath 95-10 3,025,777 3/62 Wilkenson 95-10 3,083,626 4/63 Nerwin 95-10 EVON C. BLUNK, Primary Examiner. 

1. A CAMARA INCLUDING A HOUSING HAVING A SPACE THERE IN, LIGHT-RESPONSIVE MEANS IN THE HOUSING FOR DETERMINING PROPER EXPOSURE OF A FILM IN THE CAMERA, THE LIGHTRESPONSIVE MEANS INCLUDING DIFFERENT ELECTRIC CIRCUITS FOR CHANGING THE OPERATION OF SAID LIGHT-RESPONSIVE MEANS AND INCLUDING ALSO A PLURALITY OF SWITCHES IN THE CIRCUITS AND AT SPACEDS LOCATIONS AT ONE SIDE OF SAID SPACE IN THE HOUSING, A GROUP OF FILM MAGAZINES THAT FIT INTO THE HOUSING AND INTO THE BACK OF SAID SPACE WITHIN THE HOUSING AND THAT ARE SELECTIVELY INSERTED IN THE HOUSING TO CHANGE THE FILM IN THE CAMERA, EACH FILM MAGAZINE HAVING FILM SPOOL HOUSINGS AT OPPOSITE SIDES THEREOF AND A REARWARDLY RECESSED FRONT WALL BETWEEN THE HOUSINGS AND WITH AN EXPOSURE SLOT THEREIN FOR EXPOSING A FILM THAT IS DRAWN ACROSS THE BACK OF SAID RECESSED FRONT WALL, AND AN ABUTMENT SURFACE ON THE FILM SPOOL HOUSING ON ONE SIDE OF EACH OF THE MAGAZINES, LOCATION OF THE ABUTMENT SURFACES OF THE DIFFERENT MAGAZINES CORRESPONDING WITH THE LOCATION OF DIFFERENT ONES OF THE SPACED SWITCHES, WHICH SWITCHES CLOSE THE CIRCUITS THAT ADJUST THE CAMERA FOR THE PARTICULAR FILM SPEEDS OF THE FILMS IN THE DIFFERENT MAGAZINES. 